1. Field of the Invention
This invention relates to fuel-injection systems and, more particularly, to an improved fuel manifold and supply system for supplying fuel directly to cylinder head passages exteriorly of the valve covers.
2. Description of the Prior Art
Previous fuel injection supply systems encountered problems from the need for an excessive number of fittings between a fuel source and each individual injection pump. The supply lines passed through the valve cover of the engine and into a fitting connected to each injection pump. Special connections and fittings were required to pass each supply line through the valve cover and to connect the supply line to the pump. Occasionally, the fittings in the valve cover or to the pump leaked, permitting fuel to mix with the engine lubricating oil which mixture would not provide adequate lubrication for the engine. The inadequate lubrication could cause overheating and engine damage or failure.
The necessity for the supply lines to run through and be connected to the unitary valve cover created assembly and service problems in that each time one line needed service, all of the lines had to be disconnected from the valve cover. Also, each time the valve rockers or the individual fuel injection pumps needed inspection or service, all of the supply line fittings had to be disconnected before the valve cover could be removed.
One fairly recent attempt to solve the problem entailed providing one continuous inlet conduit and one continuous outlet conduit through the engine block or cylinder head and into communication with the injection pump of each cylinder. This continuous conduit concept eliminated the fittings and possible dilution of the lubricant problem, but has the inherent defects of requiring a complicated boring operation in the engine block. Also, if the conduit becomes blocked, all cylinders downstream are left without fuel causing engine failure. The service problem to unplug the conduit is complicated and expensive, requiring substantially a complete tearing down of the engine to gain the needed access to the plugged conduit.
A second fairly recent attempt to solve the problem provides for a conduit through the side of the cylinder head directly into the injection pump with the inlet fuel being fed through an internal conduit and the return fuel passing exteriorly of the tube forming said internal conduit. This solution also has shortcomings in that the fuel must enter and leave the pump in the same area and the inlet and outlet conduits are easily blocked.